The invention generally relates to components and circuits that make up digital to analog (d/a) converters (DACs), and, more particularly, to an d/a converter having a low power semi-analog finite impulse response circuit to reduce the size of the required resistor values, reducing the occupied chip.
One conventional configuration of d/a converters has a series of resistors in a resistor bank, powered by individual voltage drivers. The series of resistors has increasing resistor values, with larger resistor values on the opposite ends. These resistor components take up the most chip space in a d/a converter circuit. In operation, digital signal values are received at the resistor banks and, according to the values, drive the voltage switches that draw current across the resistors to generate an analog waveform. This is how the digital signal is converted to an analog signal.
One motivation of circuit designers is to reduce the size of the chip space required for circuit components. In conventional DACs, the resistor values used in the DACs are large and account for the majority of the space on the chip.
If it were possible to achieve the same conversion result of a d/a converter with smaller resistor values, then chip space could be reduced. As will be seen below, the invention accomplishes this in an elegant manner.